Wednesday, July 26, 2006

On the right is a link to a post I wrote about Monton's paper: "The Infinite Universe and Dembski's Design Inference." The Maiden commented:

If I remember right, the critical density is something like one molecule of hydrogen per cubic meter. Now, imagine that universe-- one cubic meter with the equivalent of one hydrogen molecule of mass. That universe will never collapse. In fact, if the numbers are absolutely perfect that universe will be completely flat. If you double both the mass and the volume, the density stays the same. Double it. Triple it. The density won't change so long as each value goes up by the same figure, even if that figure is infinity. It should be easy to see then that it is possible to have an infinite universe with infinite mass but which never collapses.

I wanted further consideration of this comment by others more qualified. I think that what the maiden says is true as far as it goes, but the prevailing understanding of the origin of the universe is that it appeared in the Big Bang. At this point, the universe wasn't "infinitely large" - in fact, it began expanding from an infinitesimally small point. If the mass of the universe were infinite, then the expansion would not have continued. I think the maiden is correct in terms of physics, but not in terms of cosmology, but I'd like somebody who is more up to speed to comment further.

Someone like Dave Heddle, perhaps, who also stopped by to comment on the original post, and pointed out that the currently prevailing model was that the universe was flat and (presumably) finite in mass.

Although it wasn't relevant to the paper under discussion, Steve made the point that

Dembski's work, such as his paper on searching large spaces, completely ignores the impact of natural selection on the probabilities involved. Hence his probability calculations are suspect.

This isn't the case: Steve seems to have misunderstood what Dembski is talking about. Steve correctly observes that natural selection is not a chance process - which means that, since not designed, it is a "regularity". Dembski's thesis is that there is a limit to the amount of specified information that a regular process can generate. Steve's point seems to be simply that "natural selection does create specified information" - which simply contradicts Dembski with no supporting evidence.

The point of all this being that Monton's paper doesn't constitute a refutation of Dembski's work if his assumption that the universe could be infinite, or have infinite mass, is wrong. There may be other refutations, but this wouldn't be one.

If you do a search on "Stop and go with mercy", you'll discover that this is a VeggieTales song ("On the Road with Bob and Larry", "Jonah") that features in various family households. Ours isn't exempt, since we have worked through "On the Road" on several car journeys.

Our youngest (5) is a little shaky on the words, though. This morning she's been singing "Stop and Go with Percy". I'm not sure who she thinks Percy is - perhaps somebody in the van with Bob and Larry, along with "all those children in the back"!

Monday, July 24, 2006

Imagine an environment which contains a variety of resources: we might imagine these as being carbon dioxide molecules, water molecules, visible light photons, and so on. The environment will probably contain a large number of these – though not uncountably large. And even using non-specialist datatypes, a 64 bit integer will allow counting up to 1018 – a 16 byte BCD number (“decimal” in Visual Basic) will count up to 1028! So it is possible to work with pretty large populations – remember that 22.4 dm3 of gas contains only 6x1023 molecules – and of course, the same datatypes are available to count instances of particular species.

Imagine in this environment a simple proto-organism – perhaps no more than a protein; perhaps as much as a simple cellular organism. The significant thing about this proto-organism is that it is the simplest reproducing organism. If the organism has access to (say) two molecules of carbon dioxide, two molecules of water and a photon of visible light, it will reproduce, becoming two copies of the organism, and outputting (let's say) one molecule of oxygen. There are now two copies of the organism, and the environment has gained one molecule of oxygen, but lost the required input molecules and energy. (We deduce from this that the organism consists of two carbon atoms, four hydrogen atoms, and four oxygen atoms ... but that's not important right now.)

As the population of this organism grows, the number of molecules of the resources in the environment decreases. It would be possible for the environment to be replenished with each step, or for a limited amount of a particular environmental resource to be available at each step.

Now, with a finite probability, the organism might mutate. Not just generally mutate, but significantly mutate. What I mean by a “significant mutation” is that it changes what it uses from the environment and what it returns to the environment when it reproduces. So an organism might use a molecule of oxygen instead of one of the molecules of carbon dioxide, and return a molecule of carbon dioxide when it reproduces. If this happens, we have a functionally different organism – which itself reproduces and affects the environment.

In my latest foray into Visual Basic, I started modelling this. It is possible to have mutation rates at very low levels (let's say one in 1010, for the sake of argument), so the population of an organism has to get to the sort of levels that most programs modelling evolution can't dream of before it is likely to mutate.

The number of exchanges with the environment (molecules used or returned) represent what I termed the "weight" of the organism. The higher the weight, the longer an organism takes to reproduce. If a resource in the environment is exhausted, the population of an organism that requires that resource to reproduce declines. If it is "limited" (by which, in my first attempt at modelling it, I suggested that more than 1% of the environmental resource is used in each step) the population of an organism that requires that resource won't grow.

I think this is a new approach to modelling evolution - and it is more concerned with large-scale changes in populations over time, rather than the evolution of new functionality. Indeed, this model assumes that new functionality can evolve (and that the proto-organism can appear in the first place), rather than seeking to demonstrate how this might happen, and on that basis looks at how populations might develop over time. "Tangled Nature", as developed by Henrik Jensen et al, looks at changes in large populations in this way, but I think the advantage of this approach is that it ought to be less computationally heavy but still able to yield interesting results.

Friday, July 21, 2006

Matthew Parris argued that Israel needs to go "the extra mile" to settle the argument - that is, offer more than they have to for the sake of goodwill. I suspect that Israel would argue that, by voluntarily withdrawing from Palestinian territory earlier in the year, and offering more territory, it had already done that. It's also interesting that he, a non-Christian (although one who has shown a clear understanding of the nature of the Christian message), should be arguing that a non-Christian state should operate according to a Christian ethical standard.

Their weather correspondent argued that an immediate carbon tax on aviation ought to be introduced, because aviation fuel isn't taxed. This is being repeated so often, it has almost become a mantra. In the UK, Airline Passenger Duty is already imposed - there is no comparable tax on railway or sea travel. And yet, flying is still generally cheaper than surface transport. Furthermore, whilst rail attracts huge subsidies, the airlines raise their own capital and have to operate profitably. British Airways is approaching an operating margin of 10% - although this is high, and comparable with the low-cost airlines, the historical margins of airlines are much lower. The bottom line is that any extra tax can't come from airline profits, because they don't have enough. It would be passed straight onto the consumer.

This isn't arguing against such a tax, which may be an appropriate response to increasing carbon emissions. Some airlines already want to be part of the emissions trading schemes. But it is somewhat absurd that airlines are being penalised for their commercial success when so many people long for viable surface alternatives.

Sunday, July 16, 2006

We've just spent a weekend away - camping, for the first time as a family, though not self-catering - with one of the churches that we are members of. Malcolm Macgregor spoke. A good time was had by all, I believe.

Completely disconnected, here is a list of my five favourite Disney animations, in reverse order ...

5) TarzanAn unusually good soundtrack (Phil Collins) - indeed, the only movie soundtrack I've ever bought, though I felt somewhat shortchanged afterwards. Particularly strong in the first half, where Tarzan is struggling with his identity, and his adopted mother is seeking to protect him.

2) Lilo and StitchUnexpected choice. Lovely animation, subtle but knowing plot, with references to all sorts of other films, and various issues flagged in a low-key way (genetic engineering, obsessive disorders for example).

1) The Emperor's New GrooveUnexpected choice, I imagine, but it is enjoyable and fun. A brilliant script, good characters - both the sympathetic "good guys" and the suitably villainous "bad guy" - and animation that is stylistically "retro". The restaurant scene is particularly clever, as is the chase finale. "I've turned into a cow. May I be excused?". More quotes here.

Strongly biased towards recent releases, I notice. We didn't see many films when I was growing up, and when I compare these films with those I've seen since, I just think these are stronger. Probably my favourite older one is "Jungle Book".

Disney films are, of course, generally derided by serious critics. I suppose the problem with Disney isn't in the themes it addresses - which are universal - identity, relations with parents and so on. It's that it seems to "cheapen" them, by making them commercial. But then, isn't that what every writer or film director is seeking to do, I wonder?

Tuesday, July 11, 2006

... isn't only felt by women - though Miss Mellifluous writes not only movingly but instructively. (HT Amanda). That's about the third time in the last few months that Genesis 15 has been brought to my attention.

A male acquaintance was recently told by his wife that she wants a divorce. I report this not to embarrass anyone or prejudice any legal process - neither party knows about this blog - but because it is typical of what is happening today. There are no other adults involved, apparently, but they do have children. She is not interested in counselling - she says she is doing this "for herself" - but, as my acquaintance points out, the whole point about the wedding vows is that you forego your future right to do things primarily "for yourself". She has said she doesn't want him to come back home. To what is his home as well, it should be pointed out - though the solicitor said that in such cases, "possession is nine tenths of the law".

To add financial insult to injury, in the divorce papers, she has claimed a large proportion of their assets - presumably because she expects custody of the children - and the legal advice my acquaintance has received is she can expect to get most of them. So she has chosen to walk away from a promise that she freely gave, and she can expect to benefit substantially from this.

It is frustration with this, and the helplessness that many men feel in the face of the family law system, that has led to the establishing of groups like Fathers 4 Justice. They may not be changing the world, but they are at least showing the world their frustration, and highlighting the unreasonableness of the system.

I had always assumed that Tolkein's task, in creating an entire universe from scratch, was one of the most challenging for a novelist. However, in both these cases, the work that has been done by the author to:a) bed their characters in a universe that is full of real (that is, not fictional) people, real locations and real events,b) make their stories significant butc) allow them to touch lightly enough on the world to not change history,is quite remarkable. Both books make for disturbing reading - I would not expect to see either on GCSE reading lists in the near future.

Faulks' description of the treatment of mentally ill at the end of the 19th century is particularly powerful, and he does a great deal to try and communicate the nature of schizophrenia - both from the perspective of the sufferer, and those who are close to it.

At some stage, I'd like to talk through some of the ideas that Faulks puts forward, in the mouth of one of his principal characters, Thomas Midwinter, who judging from his reception and the perspective of the writing, I think Faulks is using as a mouthpiece for some of his own thoughts on what it means to be human. For now, it is worth noting that some very thoughtful and articulate arguments are set forth, and the ideas lie in the synthesis of different branches of knowledge, rather than through a kind of reductionist insight.